The transport of electrical signals assumes a paramount character in the optimal operation of measurement systems. Indeed, poor quality of transmission can complicate, or indeed prevent, utilization of the measurements. This problem becomes all the more acute when the transmission takes place in a strongly disturbed electromagnetic environment and over large distances.
It is known that monofilar transmission poses signal propagation problems. In particular in the case of the transmission of differential signals, parasitic perturbing signals are superimposed on the useful signals, and in this case more or less complex physical shieldings are used to limit the effects thereof.
Bifilar transmission is used but in general only for measurements of current. There is no transmission of frequency signals by bifilar link, because notably of the difficulty in implementing the measurement system situated downstream. The parasitic perturbations which may appear in the current signal then remain limited to leakage currents. The presence of a guard annulus generally makes it possible to limit the impact thereof.